Time-controlled device for switches and the like



July 23, 1940. B a HQRSTMANN 2,208,902

TIME-CONTROLLED DEVICE FOR SWITCHES AND THE LIKE Filed Dec. 5. 1938 4Shets-Sheet 1 July 23, 1940. a s. HORSTMANN TIMECONTROLLED DEVICE FORSWITCHES AND THE LIKE Filed Dec. 3, 1938 4 Sheets-Sheet 2 July 23, 1940.B. e. HYORSTMANN TIME-CONTROLLED DEVICE FOR SWITCHES AND THE LIKE FiledDec.

y 1949 B. G. HGRSTMANN 2,208,

TIME-CONTROLLED DEVICE FOR SWITCHES AND THE LIKE Filed Dec. s, 1958 4Sheets-Sheet 4 Figmo 3,4575 @WKM;

Patented July 23, 1940 UNITED STATES PATENT OFFICE Bevan GrahamHorstmann, Bath, Somerset, England Application December 3, 1938, SerialNo. 243,848 In Great Britain May 20, 1938 12 Claims.

This invention relates to time controlled devices of the kind in which amember to be controlled such as an electric switch or gas valve can bemoved into one position (e. g. on") and held in that position for apredetermined operative time interval--which is usually adjustable-atthe expiration of which the switch or the like is moved automatically toanother position (e. g. oil). Time controlled devices of this nature areoften associated with electric switches or gas valves whereby theelectric or gas supply may be brought into use for present periods asdesired, a particular application being to electric or gas cookingappliances to enable 18 a required cooking period to be placed under thecontrol of the device so as to be terminated automatically at theselected time. In this kind of device a timepiece drives an adjustableactuating device for the switch or valve which sometimes takes the formof tappets or levers adjustable in relation to a time-graduated drivendial, or which may be any other suitable device capable of setting inrelation to the timepiece drive to bring the controlled switch or valvereferred to herein as the period member, controlling as it does thecommencement and cessation of the operative period of the switch, valveor other element under control.

The object of the present invention is to provide a time controlleddevice of the above described kind in which the pre-set operative timeperiod can be caused to commence functioning either at the time ofsetting the period member, or at any selected time thereafter by settingan auxiliary member termed herein a "delay member which is alsotimepiece driven, and adjustable to set a pre-arranged time period todelay th commencement of the actual operative period. Thus in theapplication of the device to an electric or gas cooking appliance, thecooking periodthe length of which can be pre-set as desired by theperiod member-may be delayed so as to come into operation as and whenmay be required.

According to this invention there is provided time controlled mechanismapplicable to electric switches, gas valves or other devices to becontrolled, comprising a timepiece, a period member adjustable topre-set an operative time period for the device to be controlled andadapted to be driven by the timepiece through a coupling, a delay memberalso adapted to be driven by the 5.5 timepiece and manually adjustableto pre-set a time delay interval and at the setting simultaneously touncouple the drive between the timepiece and period member, and meanswhereby the delay member automatically re-couples the period memberdrive at the termination of the 5 delay interval to start the drive ofthe period member and commence the pre-set operative time period.

Some practical embodiments of the invention 'will be described by way ofexample as applied to the control of an electric switching deviceparticularly intended for use with an electric cooker, these embodimentsbeing illustrated in the accompanying drawings wherein:

Figure 1 is a front elevation of one embodiment;

Figure 2 is a section on the line IIII of Figure 1;

Figure 3 is a detail view of the switching arrangement;

Figure 1- is front elevation of the second embodiment;

Figure 5 is a section on the line VV of Figure 4;

Figure 6 an elevational view with dials removed u to show the switchactuating mechanism of the embodiments of Figures 4 and 5;

Figure 7 is a side elevation looking from the left hand side of Figurel, and serves primarily to show the relative disposition of the switchactuating part;

Figure 8 is a front elevation of the third embodiment;

Figure 9 is a section on the line IXIX of Figure 8; and Figure 10 is adiagram of the switching arrangement in the synchronous motor and heatercircuits.

Referring to the first embodiment the adjustable period mechanismconslsts of a control knob l which is axially displaceable on butrotatable with a spindle 2 which is rotated by a synchronous motordriven clock movement generally designated 3. Behind the control knob land surrounding the spindle 2 are two dials, the outer dial 4 beingreferred to hereinafter as the pre-set time period or cook dial and thesecond as the delay dial 5. The control knob 5 drives the delay dial 5by means of a primary pin 5 on the latter projecting through an armateslot 7 in the cook dial into a socket 8 in the control knob, whilst areleasable driving connection to the cook dial 4 is provided by pins 91on the hub of the cook dial which engage in sockets carried by thecontrol knob.

The cook dial is permitted a maximum movement in one direction-sayclockwise, this movement corresponding to the longest cooking periodprovided, and to switch on the device, the control knob I is turned byhand in this direction to the maximum permitted extent, carrying with itboth dials 4 and 5. The result of this movement is to close thesynchronous motor and heater circuits, after which the control knob withthe dials is turned back through a distance which subtracted from themaximum permitted movement leaves a complementary distance correspondingto the predetermined operative time period required. Under the action ofthe synchronous motor clock movement, the knob and the dials willcontinue to rotate backwards until this complementary distance has beentaken up-which means the termination of the operative time period-andthe knob or cook dial is provided with means such as a pin which thenopens the switches controlling the synchronous motor and heatercircuits.

As above described the required operative time period 1. e. cookingperiod starts as soon as the cook dial 4 has been set. To delay thecommencement of this time period, the two dials 4 and 5 are set asbefore by means of the control knob I, and the latter is then pulledaxially away from the dials against the action of a spring l enclosedwithin the control knob and abutting the head of the driving spindle 2.This axial displacement of the control knob releases the driving pins 9on the cook dial 4 from the sockets on the control knob, but the primarypin 6 of the delay dial, which is longer than the pins 9, remains inengagement with the control knob so that the delay dial can now beturned forward by hand without aifecting the setting of the cook dial.It will be observed that the cook dial 4 is mounted on a fixedsleeve-like boss H in the enclosing casing I2, with the outer portion ofa friction ring l3 which, whilst it permits setting of the cook dial andthe driving thereof by the synchronous motor when the two dials arecoupled together nevertheless, serves to retain the cook dial inadjusted position during setting and return of the delay dial. Furtherit will be observed that when the delay dial is uncoupled from the cookdial, it can rotate freely on the hub M of the cook dial.

The distance the delay dial 5 is turned forward to displace the twodials angularly as above described, will depend on the time intervalwhich is required to take place before the operative preset time periodset on the cook dial 4 begins to function. During the delay period thecontrol knob i and the delay dial 5 will be rotated backward by thesynchronous motor movement, but

the cook dial 4 will remain stationary until the driving pins 9 on thehub l4 register with the corresponding sockets of the control knob, thecontrol knob then moving axially inwards under the action of the springI 0 thereby to lock the cook dial 4 to rotate with the control knob land delay dial 5 so that the predetermined operative time periodcommences. In Figure 10, the circuit connections for the heater I 5 andthe synchronous motor 3 are shown schematically. In this circuitarrangement the synchronous motor circuit includes the supply leads I 6and a primary switch II which normally i. e. in the zero position of thetwo dials is open, whilst the circuit for the heater l5 includes thesupply leads I6, the primary switch l1 and a secondary switch 58 whichis normally closed. Consequent upon setting of the cook dial 4, theprimary switch I! is closed thus establishing the synchronous motor andheater circuits, and this switch will only open again at the end of thepre-set operative time period when the two dials have returned to theirzero position. When the delay dial is set, however,-it causes the heatercircuit to be broken at the switch l8, which circuit is reestablished assoon as the control knob i moves inwards to commence the predeterminedoperative time period. For this purpose the normally closed contacts ofthe switch l8 are controlled by a member which is carried by the knoband adapted to open the contacts as the knob is displaced axiallyoutwards and to close them again as the knob moves inwards. A suitableconstruction for efl'ecting this operation is shown in the embodimentillustrated in Figures 4 to '7, and

may be applied here.

Suitable time scales I9 and 2|l may be provided on the two dials 4 and5, which move past a window 2| in the casing l2 of the device, the scaleE9 on the cook dial 4 being set in relation to the left hand edge 22 ofthe window 2| and the delay dial scale 20 in relation to the edge 23 ofthe cook dial 4.

In the drawings, the mechanism is shown adjusted to give an operativetime period of three hours,.and a delay period of one hour as will beseen from an inspection of Figure 1.

Any suitable form of switching arrangement may be incorporated in thedevice, but a convenient and simple form is that illustrated in theaccompanying drawings. Thus for actuating switch contacts of theswitches l1 and ill in the synchronous motor and heater circuits, thereis provided a one-armed actuating lever 24 which is pivoted at 25 to theinner wall of the casing 26 for the switch contacts, and which carriesat its free end a roller 21 adapted to ride on the periphery of a camplate 28 under the action of spring pressing on the actuating lever. Forthis purpose the inherent resilience of the contacts of the primaryswitch I! is utilised, the latter being mounted horizontally under theactuating lever, so that the upper movable contact i'la in the normallyopen position, presses the lever 24 upwardly. The cam plate 28 is fixedto rotate with the cook dial 4, and at a point disposed at the end ofthe permitted movement of the latter, it has a rise 29 which moves theactuating lever 24 outwardly to close the contacts of the switch I1.Simultaneously a pin 30 on the cook dial 4 moves forward a locking camring 3! loose about the axis of the spindle 2 into engagement with theroller 21 which eventually at the conclusion of the forward movement,seats in a recess 32 in the loose ring, so that the actuating lever 24is locked in the operative position. The cook dial can now be moved backto set the required operative time period without the contacts of switchI! being affected. When this period expires, a pin 33 on the cook dialdisplaces the loose ring 3| from the roller 2'! thereby releasing theactuating lever 24 so that the contacts of switch I! open.

In the detail Figure 3, the contacts of switches l1 and i 8 are shown inthe operated positions that is to say, switch I! is closed and switch l8open, as occurs when the device has been set to provide for a delayperiod before commencing the operative time period.

In the embodiment illustrated in Figures 4 to '7, the cook dial 44 isdisposed behind the delay dial 55 which is formed integral with thecontrol knob 2,208,902 4|, and which, after setting. is drivenbackwardsby the synchronous motor movement 43 through gears 46 and 41 ofwhich gear 48 is fixed to a sleeve 48 rotatable and axially displaceableon the spindle 42 and rigid with the control knob, the latter beingpressed inwardly by a spring 56 and the width of the gear 4'! being suchthat in any axial position of the control knob the gear 46 is alwaysengaged therewith. The cook dial is coupled to the delay dial through aprojection 48 on the back of the delay dial which normally engages in acorresponding socket 49a in the cook dial. This coupling enables thecook dial to be set to a desired operative time period by manipulationof the control knob, and then both dials to be driven backward by thesynchronous motor, providing no delay has been set. Axial displacementand angular adjustment of the delay dial to set aparticular delayperiod, however, releases the coupling by disengaging the projection 49from the socket and causing the same to run on the face of the cookdial. At the termination of the delay period during backward rotation ofthe delay dial by the synchronous motor, the pro- 'ection drops into thecook dial socket 49a under the action of the spring 50, whereupon thetwo dials are re-coupled and rotate together through the angulardistance corresponding to the preset operative time period until zeroposition isreached, at which position the primary switch i! is opened sothat not only the heater circuit (but also the synchronous motor isdisconnected. The drive to the two dials therefore stops.

On and extending angularly about the head of the casing 43, is a fixedcook period scale 5i, and the cookdial is set in relation to this scaleby providing it with an annular peripheral portion 52 which embraces thedelay dial and which has a time mark 53 moving adjacent the fixed cookperiod scale. The delay dial is set in relation to the cook dial, beingprovided with a scale 5d which moves adjacent the time mark 53 on thecook dial.

The switching arrangement controlled by the two dials is arrangedas inthe previous embodiment-so that the cook dial has to be turned clockwisethe angular amount corresponding to the greatest cooking period allowedand then turned back to the point which leaves a complementary distancecorresponding to the desired operative time period. If the commencementof this period is to be delayed, the delay dial is pulled axiallyoutwards and adjusted a further amount from zero, the adjustment beingin the same direction, namely clockwise, as the setting of the cook dialuntil the desired indication on the delay scale registered with the timemark 53, the resulting angular spacing of the two dials having to betaken up before the operative period comes into operation.

When the cook dial is moved through the maximum permitted angulardistance, a pin 55 projecting from the back of the cook dial 4H andrunning in an arcuate slot 56 in the casing 43- which slot determinesthe said permitted movement-engages near the end of its travel aprojection 57 on the end of one arm of a two-armed actuating lever 58.The lever 58 swings about a pivot 59 and carries on the end of its otherarm Gil an insulated roller 6i which co-operates with the contacts ofthe primary switch H. The pin 55 upon engaging the projection of thelever 58, rocks the latter against the action of a spring 62 so that itsswitch actuating arm 60 turns anticlockwise to cause the roller 6! toclose the contacts of the switch [1 as shown in the drawings. The switchactuating lever is locked in this position by means of a shelf 63thereon which catches over a ledge 64 on a locking lever 65, controlledby a spring 66. The cook dial can thus be set back to the requiredoperative time period without aflecting the operated condition of theprimary switch contacts.

During the operative time period the pin 66 travels back with the cookdial in anti-clockwise direction, and at the termination of the periodwhen it is near the bottom end of the arcuate slot 56, it engages a lug61 on the end of the looking lever 65, thereby depressing the latterdownwardly to remove the ledge 64 from the shell on the actuating lever58, which thereupon is utilized to rock under the action of its spring6| in a direction to depress the switch actuating arm 60 and remove theroller 6| from the switch contacts; which thus open. This switching 03"takes place when the time mark 53 reaches the zero mark on the cookperiod scale 5|. To ensure that switching off takes place, should therelease of the locking lever fail to achieve the desired result, theswitch actuating arm '60 has an upward extension 68 which lies in thepath of the pin 55 so as to be engaged thereby at the end of theoperative time period, with the result that the switch actuating arm isdepressed positively.

For opening the secondary switch contacts in the heater circuit when thestart of the operative time is to be delayed, the movable contact of theswitch I8 has a tongue piece which engages in an annular recess 68a inthe back of a hub portion of the delay dial 55 whereby when the latteris pulled axially outwards to release the aforesaid coupling previous tosetting the delay period, the movable contact is moved away from theopposite contact, as will be seen from Figure 5, thus opening theswitch.

To retain the cook dial in set position during setting and throughoutthe duration of a delay period, a friction brake 69 is interposedbetween the cook dial and its mounting.

In the further embodiment of the invention disclosed in Figures 8 and 9,the delay dial 75 has a control knob ii and is secured to a spindle iiiwhich is formed at its inner end with an interiorly screw threadedsocket 12 which screws on to an exteriorly threaded spigot 18 fixed tothe casing of the synchronous motor movement generally designated 13.The inner end of the delay dial spindle carries a pinion 16 whichpermanently meshes with a pinion ll of the synchronous motor movementirrespective of the axial position of the delay dial. The member bywhich the cooking period is set comprises a knob Hi which is secured tothe periphery of an inner disc '89 mounted on a fixed sleeve tion of afriction brake band 8E. The normally open contacts of the primary switchit are disposed to one side of the delay dial and the movable contact isprovided with an extension 82 which lies in the path of an insulated pin83 projecting from the back of the disc 19. When the cook knob 14 ismoved clockwise over the fixed scale 14a to pre-set an operative timeperiod, the pin 83 moves away from the contact extension 82 so that theswitch ll closes to establish the synchronous motor and heater circuits.

In this embodiment the normally closed contacts 84 of the secondaryswitch I8 which controls the heater circuit are carried the one by thedelay dial and the other by the disc 19 to which the cook knob 14 issecured. For this purpose the 80 with the interposi-.

delay dial spindle 10 is provided with a radial arm 85 to the end ofwhich one of the contacts 84 is secured whilst the other contact iscarried by a projection 86 from the back 01 the disc 19. Brushes 81 and.88 are electrically connected respectively to one of the contacts 84and wipe over arcuate conductors 89 and 90 which are brought out to theterminal block 9| supporting the contacts of primary switch l1, andwhich are connected in the heater circuit. The contact carried by thearm 85 is in advance of the contact carried by the projection on thedisc I9, and it will be seen therefore, that as the cook knob 14 is setto a desired cooking period, the disc 79 will turn the delay dialthrough mechanical coupling provided by the contacts, the heater circuitbeing maintained through the arcuate conductors 89 and 90. If no delayperiod is required, the synchronous motor in rotating the delay dialbackward via the gearing l6 and 11 will also drive the disc l9 andthereby the cook knob ll backward through the mechanical couplingprovided by the engaging contacts 84. If a delay period is desired, thedelay dial, following the setting of the cooking period, will be turnedmanually through a further angular distance corresponding to the delayperiod required, which results in the breaking of the aforesaid couplingsince the contact carried by the arm 85 moves away from the contactcarried by the projection 86, and the heater circuit is thereby alsoopened. The delay dial is provided with scale 92 by which the setting ofdelay period may be efiected by turning the delay dial until the delayperiod indication on its scale registers with a pointer 93 on the cookknob M. At the termination of the delay period the contacts 84 willre-engage thus re-establishing the heater circuit as well as themechanical coupling through which the drive to the cook knob iseffected.

It will be observed that during rotation. of the delay dial, the.spindle ill of the latter works up and down on the screwed spigot 18,the axial movement producing a wiping action of the contacts 84.

In each of the embodiments described herein there will be provided inthe drive from the synchronous motor to the delay dial, a free wheelclutch (not shown) which permits the setting of the period and delaymembers to be effected free- 1y without movement of the synchronousmotor.

Although dials have been referred to herein they may be pointers orother suitably shaped members for enabling the required setting to bedone.

I claim:

1. Time controlled mechanism applicable to electric switches and thelike to be controlled, comprising a timepiece, a period memberadjustable to pre-set an operative time period for the device to becontrolled and adapted to be driven by the timepiece through a coupling,a .delay member also adapted to be driven by the timepiece and manuallyadjustable to pre-set a time delay interval and at the settingsimultaneously to uncouple the drive between the timepiece and periodmember, and means whereby the delay member automatically re-couples theperiod member drive at the termination of the delay interval to startthe drive of the period member and commence the pre-set operative timeperiod.

2. Time controlled mechanism according to claim 1, in which the periodmember is adjustable timepiece drives the adjusted period member in thedirection opposite to its setting, the delay member being adjustable torender the timepiece drive to the period member ineffective for apredetermined delay interval.

3. Time controlled mechanism applicable to electric switches and thelike to be controlled, comprising in combination period and delaymembers connected together through a releasable coupling by which bothmembers can be manually adjusted together in one direction from zeroposition for setting a time period, and the delay member then uncoupledto enable it to be further adjusted in the same direction independent ofthe period member, a timepiece connected to drive the delay member inthe opposite direc-- tion back to its zero position, and to drive theperiod member in the same direction when coupled tothe delay member,means whereby when the period member is uncoupled, re-coupling thereofis effected at the end of a delay interval determined by the extent ofthe independent adjustment oi the delay member, and actuating meansconnecting the two members to the device to be controlled so that theadjustment of the period member pre-sets an operative time period forthe said device, the independent adjustment and uncoupling of the delaymember rendering such pre-setting ineffective until the expiry of theset delay interval.

4. Time controlled mechanism according to claim 3, wherein the periodand delay members are coaxially mounted and adjustable angularly.

5. Time controlled mechanism according to claim 3 wherein the period anddelay measures are co-axially mounted and wherein the delay member isaxially adjustable to effect release of the coupling between the twomembers whn a delay period is to be set.

- 6. Time controlled mechanism according to claim 3 wherein the periodand delay members are coaxially mounted and are adjustable angularly,the delay member being axially adjustable to effect release of thecoupling between the two members when a delayperiod is to be set andwherein the coupling comprises a dog on one member engaging in acorresponding socket on the other member, there being a spring normallymaintaining the coupling parts in engagement,

7. Time controlled mechanism according to claim 3 wherein the period anddelay members are coaxially mounted and wherein the coupling between thetwo members comprises complementary parts one angularly in advance ofthe other so. that setting of the period member turns the delay member,and backward driving of the delay member by the timepiece turns theperiod member backward.

8. Time controlled mechanism according to claim 3 wherein the period anddelay members are provided with time scales and marks adapted to be setone against the other and in relation to a fixed scale or mark to effectthe desired presetting of the operative time and delay periods.

9. Time controlled mechanism according! to claim 3, wherein thetimepiece is a synchronous electric motor and the period member controlsa primary electric switch connected in the circuit of the motor, whilstthe delay member co-operates with a second electric switch connected inser-nnrlnw witnh is nm-mnllu nlnend and in opened when the delay memberis adjusted for a pre-determined delay period.

10. Time controlled mechanism according to claim 3, wherein thetimepiece is a synchronous electric motor and the period member controlsa primary electric switch for the motor while the delay member controlsan operating circuit including the primary switch, wherein means foractuating the two switches comprises a lever which is depressed andlocked by the setting of the period member to effect operation of theprimary switch, and a member which is displaced by axial movement of thedelay member to open the primary switch.

11. Time controlled mechanism according to claim 3 wherein the couplingbetween the two members comprises complementary parts one angularly inadvance of the other so that setting of the period member turns thedelay member, and backward driving of the delay member by the timepieceturns the period member backward, the period and delay members beingcoaxially mounted and adjustable angularly, and wherein thecomplementary coupling parts carry the contacts of the secondary switchwhich are electrically connected to brushes wiping over arcuateconductors.

12. Time controlled mechanism according to claim 3, wherein brakingmeans are provided for maintaining the period member in set positionduring setting and return of the delay member.

BEVAN GRAHAM HORSTMANN.

